1. Field of the Invention
This invention relates to the formation of battery terminal posts, and, more particularly, to improvements in the method and apparatus for forming low and high profile battery terminal posts in situ.
2. Description of the Art
The present invention deals with low and high profile battery terminal posts. Additional lead has to be added to terminal posts that are pre-formed on the battery group strap. The terminal post is positioned up through a bushing on the cover of the battery.
In the prior art, it is known to form battery terminal posts by lowering a mold over a bushing embedded in the battery cover through which a portion of an unfinished terminal post is projecting from the battery terminal group strap positioned inside the battery, and then heating the terminal posts and applying additional lead so as to fill the mold and join the additional lead with the unfinished portion of the post, and then cooling the lead to form the post.
In the prior art, there is no practical way to build up the lead from the bottom to the top within the mold. Various ways have been tried. One way is to use a torch and go around in an orbital fashion between the terminal post and the bushing. However, as soon as the hot lead begins to run down into the mold, it freezes or solidifies preventing the torch from heating any further down in the mold.
Another way is to push a hot rod down into the terminal post and, as the lead melts, continue to push the hot rod down. This is much like an old fashion pre-heated soldering iron.
Typically, the prior art teaches the use of molds which have a thermal mass that is much higher than the thermal mass of the material being cast.
The method of heating is also important. Heating the mold itself or from the outside are the two preferred methods. Attempting to heat the mold from the inside by flame, introduction of very hot lead, or a hot poker (i.e. soldering iron) is slow and complicated. It is also very difficult to place the heat where one prefers to apply it; which is near the base of the mold. In order to use prior art methods, one needs to heat more of the lead post. This causes the lead to shrink during cooling. In order to obtain a terminal of proper appearance, the lead has to be remelted.
Various problems have been noted in the prior art. As a result, in accordance with our invention, it is an object to solve these problems by placing the heat exactly where it is needed; rapidly heating and cooling the post; breaking up oxide coating by vibration or pumping the liquid lead; and making it easy to repair battery terminals by remelting the terminals.
Another desirable object is providing durability over several heat and cooling cycles.
Other objects and advantages of the invention will become more apparent from the following description with reference to the accompanying drawings.